Shiva Purana
बहुना किं प्रलापेन महाव्यापन्निवारकम् ॥ आत्मीयमस्त्रं शैवानामिदमाह महेश्वरः ॥ ९९ ॥
Of what avail is much talk? The lord has said that this is the spiritual missile to be used by the devotees of Śiva, to ward off great mishaps.
english translation
bahunA kiM pralApena mahAvyApannivArakam ॥ AtmIyamastraM zaivAnAmidamAha mahezvaraH ॥ 99 ॥
hk transliteration by Sanscript